Brief Article
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World J Stomatol. Nov 20, 2013; 2(4): 91-96
Published online Nov 20, 2013. doi: 10.5321/wjs.v2.i4.91
Accuracy of linear vs spiral tomography: Alveolar crest to sinus/nasal floor height
Mahsa Yoozbashizadeh, Seyed Ahmad Fatemitabar, Ehsan Sedighara, Arash Nikgoo
Mahsa Yoozbashizadeh, Seyed Ahmad Fatemitabar, Private Practice, Tehran 16617-56433, Iran
Ehsan Sedighara, Private Practice, Raleigh, NC 72601, United States
Arash Nikgoo, Private Practice, Prospect, Tasmania 7250, Australia
Author contributions: Nikgoo A and Fatemitabar SA designed the research plan; Yoozbashizadeh M and Fatemitabar SA performed the majority of the experiments; Sadighara E and Yoozbashizadeh M provided new analytic tools; Sedighara E analyzed the data; Yoozbashizadeh M provided financial support for this study; Nikgoo A wrote the paper.
Correspondence to: Arash Nikgoo, DDS, ADC, Private Practice, Prospect, Launceston, Tasmania 7250, Australia.
Telephone: +61-4-24545992 Fax: +61-3-63623644
Received: March 10, 2013
Revised: September 19, 2013
Accepted: October 17, 2013
Published online: November 20, 2013

AIM: To determine the accuracy of tomography in the linear measurement of alveolar bone at maxillary sinus/nose location.

METHODS: Two dry skulls each marked with 10 pairs of guttaperchas placed on buccal and lingual sides of the maxillary ridge were used in this in vitro study. The distance between the alveolar crest and the sinus/nasal floor was measured on tomographic views, prepared by linear and spiral techniques. The ridges were then sectioned so that each section would include one pair of buccal and lingual guttaperchas. The actual distances directly measured on the sections were compared to those of the equivalent tomographic sections (the magnification co-efficient was applied). Paired t-test was used to statistically analyze the data.

RESULTS: The measurement error with the application of linear tomography and spiral tomography was shown to be 0.455 ± 0.838 mm (P = 0.029) and 0.17 ± 0.78 mm (P = 0.347), respectively. There was a statistically significant difference between the liner tomography values and actual values (P = 0.029). This difference was representative of underestimation. McNamara’s test was used to assess the ± 1 mm error; 73.7% of the linear values and 84.2% of the spiral values were within the ± 1 mm error limit. McNamara’s test did not show any significant differences between the 2 methods in this regard (P = 0.625). The linear values were significantly different to the actual values (P = 0.029) but not to the spiral values (P = 0.185).

CONCLUSION: Spiral tomography has enough accuracy for the measurement of alveolar ridge height. Although linear tomography somewhat underestimates the actual values it provides satisfactory accuracy.

Keywords: Linear tomography, Spiral tomography, Maxillary sinus, Dental implants

Core tip: Maxillary partial or complete edentulism represent some challenging conditions in implant dentistry. The position of sinus/nasal floor in partial/complete edentulous maxilla determines the alveolar bone height and consequently the length of the implants that can be used. Although cone beam cone beam computed tomography and conventional computed tomography are widely used for pre-operative implant treatment planning, they are expensive and can expose patients to relatively high dose of radiation. We demonstrated that tomography can be a good substitute for conventional and cone beam computed tomography for alveolar length measurement at maxilla, although spiral tomography is more accurate than linear tomography.